Material handling systems developed for separating usable or recyclable parts from waste material generally comprise a conveyor for transporting the material to be separated from a recycling bin into a material separator assembly.
Generally, the material separator assembly includes a screw feeder for receiving the material or parts from the conveyor. The screw feeder feeds the parts from the conveyor along a horizontal path towards a chute. The parts are guided by the chute downward to a screen. The screen acts as the separator of the recyclable material from the waste material. The screen is mechanically or electrically vibrated to shake apart the waste material from the recyclable material. Therefore, the size of the mesh forming the screen determines the size of the acceptable parts to be recycled.
The parts that fall through the mesh in the screen are led to a crusher to be broken up into smaller pieces for reprocessing. The waste material is removed, usually by hand, from the top of the vibrating screen to a dumping area.
Although the use of a vibrating screen is generally successful in preventing large pieces of metal or other unwanted parts from traveling into the crusher, there are several disadvantages. Generally, the material to be recycled comprises metal shavings found in cutting fluids and discarded metal blocks remaining after machining a part. The waste material is generally swept away into one large container. The metal shavings and blocks may tangle together to create a large mass, such as a ball of metal.
The vibrating screen may be capable of separating the metal chunks from the metal shavings contained in such a ball of metal, however, the vibration may not break up the tangled mass of shavings which ordinarily would fall through the screen mesh. Therefore, the use of a vibrating screen to separate such materials creates too much waste as it does not provide a system to break apart recyclable material adequately. Instead, what was once recyclable material becomes waste material that is removed from the screen and thrown away. This system creates a great waste in material and money.
The parts that fall through the screen to the crusher are generally broken up into smaller pieces for reprocessing. In prior known crushers, it was important to prevent the introduction of uncrushable material or debris which could cause serious damage to the crusher mechanism and housing. Therefore, elaborate means were employed, typically including numerous screen grates or other devices to prevent the ingress of uncrushable material larger than the screen aperture opening area used in the internal crushing chamber.
Typically, the crusher apparatus includes a housing enclosing a rotary crusher device having a cylindrical portion of a predetermined length approximately the same as the length of the housing, with rotatable hammer arms extending generally radially outwardly from the cylindrical portion of the rotary crusher means in response to centrifugal forces caused by the rotation of the cylindrical portion. The pivotal hammer arms or extensions are capable of rotating with respect to the cylindrical portion in order to absorb any excessive impact with debris which is difficult or impossible to crush. This pivotal function of the rotatable hammer arms or extensions protects the device from serious damage to a certain degree. However, when an uncrushable item is encountered, the pivotal hammers continuously impact with the uncrushable debris causing the debris to become ballistic due to the impact with the hammer arm, thereafter subjecting the housing to subsequent impacts from the ballistic part potentially causing damage to the housing. Extensive and continuous impact with the uncrushable object by the hammer arms could also lead to damage to the hammer arms preventing the proper pivoting of the arm, or in the worst case, causing the arm to be broken off or removed with respect to the rotary cylindrical crusher member.
The present invention seeks to alleviate the problems associated with the prior known crusher apparatus. In the past, elaborate and expensive screening equipment has been employed to prevent uncrushable debris or parts from entering the crushing chamber. This precaution has primarily been necessary in order to eliminate any uncrushable debris or parts from entering into the crushing chamber, since previously there has been only one exit from the crushing chamber, i.e., through the crushed debris grate assembly. Uncrushable debris in the crushing chamber has been a problem for an extended period of time causing extensive damage to the crushing mechanism and housing. It is desirable in the present invention to overcome these perceived disadvantages of the present designs of crusher apparatuses.